Mangiferin is a natural polyphenol compound, which has a molecular formula of C19H18O11 and a molecular weight of 422. The mangiferin has a chemical structure as follows:

With respect to a mangiferin calcium salt, patent applications WO2009065287A1, WO2008061480A1, CN101461819, and CN101919839 have all disclosed the following contents: 1) in structure, the mangiferin calcium salt has a general formula compound (a), a mangiferin-3-O-calcium salt (b) and a mangiferin-3,7-O-calcium salt (c) whose structural formulae are as follows:

2) in use, the mangiferin is medically used as an insulin sensitizer, an AMP-activated protein kinase (AMPK) activator, and an agonist of the peroxisome proliferator-activated receptor.
Patent application WO2010/145192A1 has disclosed a mangiferin berberine salt. According to the CNMR data analysis disclosed on page 5 to the second paragraph on page 7 of the description of WO2010/145192A1, the mangiferin berberine salt disclosed is a compound of a mangiferin-3-O-berberine salt and a mangiferin-7-O-berberine salt. However, a ratio of the mangiferin-3-O-berberine salt to the mangiferin-7-O-berberine salt is not given in WO2010/145192A1.